Memory cards are manufactured by installing an electronic module, such as a memory chip, in a cavity provided in a card body for that purpose and fixed therein by means of an adhesive which, for example, is based on cyanoacrylate. Cards made in this way are stacked or stored in such a manner that a surface of one card adjoins or abuts the surface of the adjoining card.
It is often observed that the cards sustain some damage when stored in this way immediately after the operation of fixing the module to the card body. The damage occurs on an area of each card that is located facing an electronic module. Depending on circumstances, the damage occurs to a transparent protective varnish, to a transparent protective plastic layer, or to the printing ink. The damage is believed to be the result of degassing from the adhesive used. It may be of little consequence when exposure to such degassing happens to cards that do not have any pattern formed on a surface thereof. However, exposure of cards having a more elaborate visual appearance on their outer surfaces to such degassing is unacceptable due to the resultant damage which they sustain.
Cards are stored together in this way generally for the purpose of facilitating a subsequent processing such as, for example, handling, storage, shipping, and/or additional operations. In particular, cards may be subjected to personalization processing for a specific user, such as marking and applying magnetic tracks. The cards are stored against one another since that is how they need to be presented for such processing. The subsequent processing may take place either in the factory or on a customer's premises. For example, operations such as packaging in individual envelopes or personalization take place on customer premises. The term "processing" must be understood broadly. It may comprise no more than a handling operation or it may comprise an operation that is much more sophisticated.
A solution to this card damage problem which requires changing either the adhesive or changing the varnish or protective layer is not desirable. Each of these substances is presently chosen on the basis of an optimum compromise of respective properties and advantages. The particular adhesive is used for its effectiveness, and the protective layer or varnish is used for a collection of properties and, in particular, its ability to dissipate static electricity, to retain a magnetic track, and to withstand scratching.
Another solution would avoid the deterioration of cards in this way by delaying storage thereof for a certain period of time until the degassing of the adhesive ends. A further solution is to store the cards temporarily in a receiving element where they are kept apart from one another. In some cases, the machine which manufactures the cards can have a storage magazine in which the cards are kept separated from one another. These solutions are incompatible with meeting delivery deadlines, since the time required for degassing is relatively long, and may be as much as several days. Also, they would require a considerable amount of space to store the cards and would tie up goods in progress.
Another drawback of using such a receiver element is that it does not facilitate subsequent operations. Cards would need to be handled one by one to group them together for subsequent processing.